Background: Over 60% of women and men interviewed in the Tanzania Demographic Health Survey (TDHS) of 1996 and the Tanzania Reproductive and Child Health Survey (TRCHS) of 1999 indicated that they would like to be tested for AIDS virus (HIV-antibody test). This is encouraging in view of the fact that voluntary HIV testing coupled with appropriate counselling is now believed to be quite effective for the prevention of HIV infection. This paper seeks to identify some socio-demographic factors that are associated with desire for HIV testing in Tanzania. Methods: The study used data from the 1999 Tanzania Reproductive and Health Survey in which 4029 women and 3542 men were interviewed. A logistic regression analysis was used to identify correlates of desire for HIV testing for both men and women. Results: For both men and women the logistic regression results show that significant correlates of desire for HIV testing are education, residence and knowledge of HIV prevention. In particular the odds of desire for AIDS test were found to be lower for respondents with secondary school education than those with primary school education. The odds were also significantly lower for urban respondents than for rural ones. The findings further show that the odds of desire for having an AIDS test were lowest for respondents with no knowledge of HIV prevention. Conclusions: Strategic campaigns to convince people to go for HIV testing should put more emphasis on radio programmes since these are effective means of communication in rural areas where desire for testing seems to be high. Such programmes should also focus on raising awareness on HIV prevention. HIV testing facilities should also be extended to the rural areas and be offered at affordable prices.